There have been proposals for wind turbine and autogiro boats for more than a century. Wind turbine boats typically use a horizontal or vertical axis wind turbine to drive a propeller, which in turn powers the boat, while autogiro boats use thrust forces on rotating vanes directly to power a boat. The promise has always been that one need not know how to sail to operate a wind turbine boat, and can move directly into the wind, and directly downwind faster than the wind speed. While there have been many proposals, instances of practical use of these technologies are few and far between. In fact, the Amateur Yacht Research Society publication AYRS 120-1 (pages 48-64) actually suggests that a horizontal axis wind turbine multihull boat is impractical, and cannot go directly into the wind.
The failure of practical application of wind turbine technology to watercraft may be due to a failure to properly meld existing components into an optimum combination. The failure may also be due to the lack of a suitable drive mechanism, incorrect selection of the wind turbine configuration, the failure to properly deal with safety issues, the lack of an appropriate assist mechanism for when there is insufficient wind either before embarking on or during a journey, what to do with the wind turbine when docked, or a combination of these and other factors. In any event, according to one aspect of the present invention, a wind turbine watercraft is constructed that will be operational and can power directly into the wind, and overcomes all of the difficulties mentioned above. However the invention is not limited to a wind turbine watercraft alone, but rather includes as separate and distinct concepts: a new water propulsion system in general that can be powered by other forces than wind power (e.g. by human power, electric or fossil fuel motors, etc.); a modified Savonius wind turbine per se; a collapsible vertical axis wind turbine in general; a manual assist for a wind turbine; and a power transmitting mechanism suitable for use in a variety of low rpm environments not just on watercraft. The invention also relates to a method of retrofitting already existing common multihull sail boats for wind turbine powering, and the retrofit boat so produced.
According to one aspect of the present invention there is provided a multihull watercraft (e.g. a catamaran or trimaran) having a vertical axis wind turbine and connected propulsion mechanism removably mounted thereto so that the watercraft may be used as a wind turbine powered craft or a sail boat. In one form of the invention, the craft comprises a crossbar extending between two hulls adjacent the front thereof, and a rotating shaft of the wind turbine is removably mounted to the crossbar. The rotating shaft may be removably mounted in a tube connected to the crossbar. The wind turbine may be a sculptured wind turbine, a Savonius [also sometimes popularly referred to as an “S-rotor” wind turbine] or modified Savonius wind turbine, a vertically collapsible wind turbine, or other vertical axis types. The watercraft may include a dolphin striker post and dolphin striker rod, and with the tube also connected to at least one of the dolphin striker post and rod. While the existing fore crossbar of a conventional catamaran may be utilized, an added crossbar may be provided fore of the existing crossbars for mounting the wind turbine.
A method of using the watercraft described above to retrofit it from an existing commercial catamaran sailboat having a fore cross-bar (either existing, or added) to a wind turbine boat, comprises the following: Connecting a vertical axis wind turbine shaft supporting element to the fore cross-bar; operatively connecting a shaft of a vertical axis wind turbine into operative engagement with the shaft supporting element. Removably mounting a propulsion system to the catamaran. And operatively connecting the shaft of the wind turbine to the propulsion system. In this way the wind turbine and propulsion system may be removed and a sail mast reconnected to the fore crossbar.
According to another aspect of the present invention, there is provided a watercraft comprising: a vertical axis wind turbine including a shaft; a propulsion mechanism operatively connected to the shaft; and a manual assist operatively connected to the shaft. The watercraft is preferably as described above (i.e. a multi-hull).
The propulsion mechanism may comprise a first gear connected to the shaft for rotation therewith and linear movement therealong, a second gear operatively mounted to a propeller shaft of a substantially horizontal propeller, and a lever operated lifting mechanism which moves the first gear along the shaft between positions engaging, and disengaged from, the second gear. Typically, the lifting mechanism and first gear have cooperating surfaces of low friction material, whereby the lifting mechanism functions only as a clutch, or high friction material, whereby the lifting mechanism functions as a clutch and brake.
The propulsion mechanism may further comprise a third gear operatively connected to the shaft for rotation therewith, and positioned with respect to the first and second gears so that the third gear can be moved into operative engagement with the second gear simultaneously with moving the first gear out of engagement with the second gear, so that the propeller can be rotated to selectively move the watercraft forward or in reverse. The gears may be bevel or miter gears. The propeller shaft may make an angle of between about 10-16 degrees with respect to the horizontal. The horizontal propeller may be mounted so that it is partially in and partially out of the water during normal loading of the watercraft, e.g. the propeller may have a diameter of about ten-fourteen inches and be approximately half in and half out of the water.
Instead of using gears, cams, or other mechanical elements, a flexible drive shaft may be provided between the vertical axis wind turbine and the horizontal propeller. A clutch may be provided in the flexible shaft.
Instead of a horizontal propeller, the propulsion mechanism may comprise an oscillating fishtail or sculling oar simulating mechanism, or a vertical axis propeller, or a paddlewheel assembly.
According to another aspect of the invention, a watercraft propulsion mechanism per se is provided comprising: a drive element operatively connected to a rotatable shaft; and an oscillating element having a relatively rigid first end operatively connected to said drive element, and a flexible material free second end simulating a fishtail or sculling oar. The drive element may comprise a crank arm operatively connected to the oscillating element by a guide element, one of the oscillating element and guide element having a pin and the other a slot receiving the pin. Alternatively, the drive element may comprise a cam operatively connected to the oscillating element by a cam follower. The cam may comprise a lobed cam, and the cam follower engages the cam lobes. Alternatively, the cam may include a cam track, with the cam follower riding in the cam track. In another modification the drive element comprises a crank arm pivoted to a lever, in turn pivoted to a rack reciprocating generally horizontally (e.g. from bow to stern on a boat), and a pinion on a generally vertical shaft cooperating with the rack.
In the fishtail simulating propulsion mechanism, the flexible material may have a durometer of between about 40-100, and at least one supporting rib. Also, a portion of the oscillating element containing the flexible material may make an angle of between about 5-25 degrees with respect to a portion of the oscillating element containing the cam follower. The oscillating element may have a range of oscillation of between about 10-45 degrees. The drive element is preferably connected to a vertical axis wind turbine.
According to yet another aspect of the present invention a drive mechanism is provided comprising: a shaft; a first bevel or miter gear connected to the shaft for rotation therewith and linear movement therealong, a second bevel or miter gear operatively mounted to a driven element; a lever operated moving mechanism which moves the first gear along the shaft between positions engaging, and disengaged from, the second gear; and a third bevel or miter gear operatively connected to the shaft for rotation therewith, and positioned with respect to the first and second gears so that the third gear can be moved into operative engagement with the second gear simultaneously with moving the first gear out of engagement with the second gear, so that the driven element can be rotated to selectively move clockwise or counterclockwise. The gears may be spaced so that the first and third gears are movable to a neutral position in which the second gear is not engaged by either the first or third gears. The driven element may comprise a propeller shaft connected to a substantially horizontal boat propeller, and the propeller shaft may make an angle of between about 10-16 degrees with respect to the horizontal, and/or be positioned so that it is partially in, and partially out of, the water during normal loading of a watercraft with which the propeller is associated. The lever operated moving mechanism may comprise a collared gear tube connected to the first gear, and a generally fork-shaped plate or bar substantially surrounding the gear tube and engaging the collar between the collar and first gear to move the first gear and gear tube. The first gear may be splined to the shaft, and the plate or bar and collar may have cooperating low friction material surfaces. The gear tube undersurface and the plate or bar upper surface may be of low friction material, so that the device functions only as a dutch, or high friction material, so that the device functions as a clutch and brake (significantly slowing, or stopping, rotation of the shaft).
According to another aspect of the present invention there is provided a modified Savonius wind turbine comprising a pair of opposite curved vanes connected together by a perforated central shaft, which allows spillover from one vane to the other to increase efficiency. The vanes may have planar portions, and the central shaft has flat portions to which the vane planar portions are affixed.
According to yet another aspect of the present invention, a manual assist is provided for a watercraft having a vertical axis wind turbine having a substantially vertical drive shaft. The manual assist may comprise one or both of primarily arm and leg powered drive assemblies. For example, the manual assist arm powered drive assembly comprises a handle connected to a first substantially inextensible cord; a first cord drum mounted to the wind turbine shaft by a first one-way clutch; and a first take-up device (such as a torsion spring, recoil mechanism, flexible band, or the like) which takes up the cord on the drum after pulling force on the handle is released. The first cord may be connected through one or more re-directing elements (such as pulleys) from the handle to the first drum, and the handle may be mounted above an aft portion of a hull of a multihull watercraft (e.g. catamaran).
The manual assist may also comprise a leg powered drive assembly, such as a reciprocal seat mounted above the hull aft portion, with a second substantially inextensible cord connected to the seat for reciprocation therewith, and a second drum connected by a second one-way clutch to the wind turbine shaft. A second take-up device is connected to the second drum. Mounted just fore of the seat may be foot plates against which an operator may press his/her feet during reciprocating movement of the operator on the seat. A support arm may extend upwardly from the foot plates, and cooperate with both the first and second cords.
According to still another aspect of the present invention there is provided a method of retrofitting an existing commercial catamaran having a front cross-bar from a sail boat to a wind turbine boat, comprising: connecting a vertical axis wind turbine shaft supporting tube to the front cross-bar, inserting a shaft of a vertical axis wind turbine into the tube, removably mounting a propulsion system to the catamaran, and operatively connecting the shaft of the wind turbine to the propulsion system. The method may further comprise removing the wind turbine and propulsion system, and reconnecting a sail mast to the front crossbar.
According to another aspect of the invention there is provided a method of powering a land based powered mechanism at a dock using a watercraft having a vertical axis wind turbine operatively connected to a propulsion system, comprising: disconnecting the propulsion system from the wind turbine at a dock; connecting the wind turbine to a land based powered mechanism, such as a pump or generator; and reconnecting the propulsion system to the wind turbine to move the watercraft in water.
According to yet another aspect of the present invention there is provided a multihull watercraft comprising: a plurality of hulls; a propulsion mechanism mounted between two of the hulls; a vertical axis wind turbine operatively mounted to at least one hull, the wind turbine having a shaft; and an operative connection between the wind turbine shaft and the propulsion mechanism, the operative connection including a clutch. Preferably the vertical axis wind turbine comprises a Savonius wind turbine.
The watercraft may further comprise a mechanism which prevents useless spinning of the vertical axis wind turbine when the watercraft is docked (such as various vertically collapsible designs of the wind turbine, a shroud placed over the wind turbine, a connection of the wind turbine to a pump or generator at the dock, a linkage construction allowing collapse of the wind turbine in a manner not properly described as “vertically”, a readily detachable vane embodiment, a conventional umbrella collapse configuration, etc.).
A bottom-supported construction of vertically collapsible wind turbine comprises a main vane support releasably connected by one or more fasteners (e.g. screws, pins spring-pressed from the shaft, quick release fasteners, etc.) to a vertical wind turbine shaft, with curved spokes extending radially outwardly therefrom. At least two other vane supports, including an upper vane support, are provided vertically spaced along the shaft from the main vane support. The spokes on the main vane support cooperate with spokes on other vane supports to support vanes of collapsible material (e.g. woven polyester cloth, or kite material). The main vane support and upper vane supported are releasably rigidly connected together by one or more vertical supports connected to the vane supports with quick release fasteners. By first collapsing the main vane support (by removing the fastener(s) connecting it to the shaft) access is readily gained to the quick release fasteners, to allow removal thereof to collapse, in turn, all of the upper vane supports.
The linkage construction of the vane collapse system comprises a main vane support reciprocal along the length of a vertical wind turbine shaft and having a plurality of curved spokes extending substantially radially outwardly therefrom. The spokes are pivoted to the main vane support for pivotal movement about a horizontal axis. Upper spokes are pivoted to the shaft also for pivotal movement about a horizontal axis, and a vertical link is pivotally connected to the main vane support and upper spokes at or near the free ends thereof. Upper vane supports move with the main vane support, being connected thereto by vertical supports. Holes in the main vane support receive pins spring-pressed from the shaft to hold the main vane support in operative and collapsed positions. The bottom edges of the vanes are releasably connected to the spokes of the main vane support (and upper vane supports), such as by snap fasteners, hook and loop fasteners (e.g. VELCRO®), eyelets and rotatable tabs, or the like.
The readily detachable vane embodiment simply uses the releasable connection of the vanes described in the preceding paragraph with substantially rigid (not pivoted) spokes. In this embodiment the upper spokes are preferably attached to vane supports instead of the shaft, and the vertical supports between the spokes are optional.
The propulsion mechanism of the watercraft may comprise a horizontal propeller having a diameter of about ten-fourteen inches, and a large pitch. The multihull watercraft may still further comprise a seat mounted on an aft portion of one of the hulls, a device which selectively maintains the seat in a stationary position, or allows reciprocation thereof fore and aft along the hull, a substantially inextensible cord operatively connected to the seat for movement with it, a cord drum mounted by a one-way clutch to the wind turbine shaft, and a take-up mechanism operatively mounted to the cord drum, so that an operator powering movement of the seat fore and aft assists in powering the propulsion mechanism.
The invention, and its various aspects, will be described more fully—but in a non-limiting manner—with respect to the included drawings.